Semiconductor Thin Films Combined With Metallic Grating for Selective Improvement of Thermal Radiative Absorption/Emission

2009 ◽  
Vol 131 (3) ◽  
Author(s):  
C. J. Fu ◽  
W. C. Tan
Keyword(s):  
Thin Films ◽  
High Energy ◽  
Semiconductor Layer ◽  
Metallic Grating ◽  
Rigorous Coupled Wave Analysis ◽  
Semiconductor Thin Films ◽  
Wide Range ◽  
Potential Applications ◽  
Rigorous Coupled Wave ◽  
Energy Conversion Devices

We propose in this work a structure of semiconductor thin films combined with a one-dimensional metallic grating, which allows for selective improvement of thermal radiative absorptivity (also emissivity) of the structure. Both shallow and deep gratings are considered in this work. Our numerical results obtained with a 2D rigorous coupled-wave analysis algorithm demonstrate that the proposed structure exhibits enhanced spectral absorptivity for photon energy slightly above the gap energy of the semiconductor (silicon in this work). Furthermore, the selectively improved absorptivity can be obtained in a wide range of incidence angles. As such, much smaller thickness of the semiconductor layer is required to absorb the same amount of high energy photons than in a conventional Si-based photovoltaic device. In addition, absorptivity for low energy photons in the new structure is lower due to the smaller semiconductor layer thickness. Therefore, the new structure may have potential applications in energy conversion devices.

Semiconductor Thin Films Combined With Metallic Grating for Selective Improvement of Thermal Radiative Absorption/Emission

2008 ◽  
Author(s):  
Ceji Fu ◽  
Wenchang Tan
Keyword(s):  
Thin Films ◽  
Semiconductor Layer ◽  
Surface Polaritons ◽  
Metallic Grating ◽  
Semiconductor Thin Films ◽  
Wide Range ◽  
Diffracted Waves ◽  
Potential Applications ◽  
Rigorous Coupled Wave ◽  
Grating Region

We propose in this work a structure of semiconductor thin films combined with a one-dimensional metallic grating which allows for selective improvement of thermal radiative absorptivity (also emissivity) of the structure. We numerically demonstrate with a 2-D rigorous coupled-wave analysis (RCWA) algorithm that the proposed structure exhibits enhanced spectral absorptivity (for p-polarization) for photon energy slightly above the gap energy of the semiconductor (silicon in this work). The enhanced absorptivity is explained as due to excitations of surface polaritons (SPs) in the grating region, along with interactions of multiple-order diffracted waves in the semiconductor layer. Furthermore, the enhanced absorptivity of the structure can be achieved for a wide range of incidence angles so that it may have potential applications in energy conversion purposes.

scholarly journals The Growth of Semiconductor Thin Films Studied by RHEED

1990 ◽  
Vol 43 (5) ◽  
pp. 583
Author(s):  
GL Price
Keyword(s):  
Thin Films ◽  
Surface Science ◽  
High Vacuum ◽  
High Energy ◽  
Ultra High Vacuum ◽  
Large Area ◽  
Growth Modes ◽  
Semiconductor Thin Films ◽  
Wide Range ◽  
Recent Developments

Recent developments in the growth of semiconductor thin films are reviewed. The emphasis is on growth by molecular beam epitaxy (MBE). Results obtained by reflection high energy electron diffraction (RHEED) are employed to describe the different kinds of growth processes and the types of materials which can be constructed. MBE is routinely capable of heterostructure growth to atomic precision with a wide range of materials including III-V, IV, II-VI semiconductors, metals, ceramics such as high Tc materials and organics. As the growth proceeds in ultra high vacuum, MBE can take advantage of surface science techniques such as Auger, RHEED and SIMS. RHEED is the essential in-situ probe since the final crystal quality is strongly dependent on the surface reconstruction during growth. RHEED can also be used to calibrate the growth rate, monitor growth kinetics, and distinguish between various growth modes. A major new area is lattice mismatched growth where attempts are being made to construct heterostructures between materials of different lattice constants such as GaAs on Si. Also described are the new techniques of migration enhanced epitaxy and tilted superlattice growth. Finally some comments are given On the means of preparing large area, thin samples for analysis by other techniques from MBE grown films using capping, etching and liftoff.

scholarly journals A Slot-Die Technique for the Preparation of Continuous, High-Area, Chitosan-Based Thin Films

Polymers ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1566
Author(s):  
Oliver J. Pemble ◽  
Maria Bardosova ◽  
Ian M. Povey ◽  
Martyn E. Pemble
Keyword(s):  
Thin Films ◽  
Mechanical Properties ◽  
High Volume ◽  
Mechanical Anisotropy ◽  
Diverse Range ◽  
Direction Parallel ◽  
High Area ◽  
Wide Range ◽  
Slot Die ◽  
Potential Applications

Chitosan-based films have a diverse range of potential applications but are currently limited in terms of commercial use due to a lack of methods specifically designed to produce thin films in high volumes. To address this limitation directly, hydrogels prepared from chitosan, chitosan-tetraethoxy silane, also known as tetraethyl orthosilicate (TEOS) and chitosan-glutaraldehyde have been used to prepare continuous thin films using a slot-die technique which is described in detail. By way of preliminary analysis of the resulting films for comparison purposes with films made by other methods, the mechanical strength of the films produced was assessed. It was found that as expected, the hybrid films made with TEOS and glutaraldehyde both show a higher yield strength than the films made with chitosan alone. In all cases, the mechanical properties of the films were found to compare very favorably with similar measurements reported in the literature. In order to assess the possible influence of the direction in which the hydrogel passes through the slot-die on the mechanical properties of the films, testing was performed on plain chitosan samples cut in a direction parallel to the direction of travel and perpendicular to this direction. It was found that there was no evidence of any mechanical anisotropy induced by the slot die process. The examples presented here serve to illustrate how the slot-die approach may be used to create high-volume, high-area chitosan-based films cheaply and rapidly. It is suggested that an approach of the type described here may facilitate the use of chitosan-based films for a wide range of important applications.

Rigorous Coupled Wave Analysis of Surface Plasmon Resonance Sensor Based on Metallic Grating

2011 ◽  
Vol 211-212 ◽  
pp. 465-468
Author(s):  
De Wei Chen
Keyword(s):  
Surface Plasmon Resonance ◽  
Surface Plasmon ◽  
Plasmon Resonance ◽  
Diffraction Order ◽  
Wave Analysis ◽  
Metallic Grating ◽  
Rigorous Coupled Wave Analysis ◽  
Resonance Sensor ◽  
Rigorous Coupled Wave ◽  
Coupled Wave

Since the development almost a decade ago of the first biosensor based on surface plasmon resonance (SPR), the use of this technique has increased steadily. In this study, we theoretically investigated the sensing character of SPR sensor with reflection type metallic with Rigorous Coupled Wave Analysis (RCWA) method, and the mechanism is analyzed by the field distribution. It is found that the sensitivity of negative diffraction order, which goes higher quickly as the resonant angle increases, is much greater than that of positive diffraction order.

scholarly journals Trends in the Design of New Isobaric Labeling Reagents for Quantitative Proteomics

Molecules ◽  
2019 ◽  
Vol 24 (4) ◽  
pp. 701 ◽  
Author(s):  
Remigiusz Bąchor ◽  
Mateusz Waliczek ◽  
Piotr Stefanowicz ◽  
Zbigniew Szewczuk
Keyword(s):  
Mass Spectrometry ◽  
Quantitative Proteomics ◽  
Chemical Properties ◽  
High Energy ◽  
Tandem Mass ◽  
Peptide Molecule ◽  
Wide Range ◽  
Potential Applications ◽  
Isobaric Tag ◽  
Modern Mass

Modern mass spectrometry is one of the most frequently used methods of quantitative proteomics, enabling determination of the amount of peptides in a sample. Although mass spectrometry is not inherently a quantitative method due to differences in the ionization efficiency of various analytes, the application of isotope-coded labeling allows relative quantification of proteins and proteins. Over the past decade, a new method for derivatization of tryptic peptides using isobaric labels has been proposed. The labels consist of reporter and balanced groups. They have the same molecular weights and chemical properties, but differ in the distribution of stable heavy isotopes. These tags are designed in such a way that during high energy collision induced dissociation (CID) by tandem mass spectrometry, the isobaric tag is fragmented in the specific linker region, yielding reporter ions with different masses. The mass shifts among the reporter groups are compensated by the balancing groups so that the overall mass is the same for all forms of the reagent. Samples of peptides are labeled with the isobaric mass tags in parallel and combined for analysis. Quantification of individual peptides is achieved by comparing the intensity of reporter ions in the tandem mass (MS/MS) spectra. Isobaric markers have found a wide range of potential applications in proteomics. However, the currently available isobaric labeling reagents have some drawbacks, such as high cost of production, insufficient selectivity of the derivatization, and relatively limited enhancement of sensitivity of the analysis. Therefore, efforts have been devoted to the development of new isobaric markers with increased usability. The search for new isobaric markers is focused on developing a more selective method of introducing a tag into a peptide molecule, increasing the multiplexicity of markers, lowering the cost of synthesis, and increasing the sensitivity of measurement by using ionization tags containing quaternary ammonium salts. Here, the trends in the design of new isobaric labeling reagents for quantitative proteomics isobaric derivatization strategies in proteomics are reviewed, with a particular emphasis on isobaric ionization tags. The presented review focused on different types of isobaric reagents used in quantitative proteomics, their chemistry, and advantages offer by their application.

Preparation and CO2 Gas Sensitive Properties of CuO-SrTiO3-Based Semiconductor Thin Films

2007 ◽  
Vol 280-283 ◽  
pp. 311-314 ◽  
Author(s):  
Yan Fei Gu ◽  
Hui Ming Ji ◽  
Bin Zhang ◽  
Ting Xian Xu
Keyword(s):  
Thin Films ◽  
Chelating Agents ◽  
Sol Gel ◽  
X Ray Diffraction ◽  
Good Resistance ◽  
Gas Sensitivity ◽  
X Ray ◽  
Semiconductor Thin Films ◽  
Wide Range ◽  
Ft Ir

CuO-SrTiO3-based thin films were prepared by novel sol-gel technology on Al2O3 substrates using Cu(NO3)2, SrCl2 and TiCl4 as the starting materials, critic acid and ethylene glycol as chelating agents. CO2 sensing properties of the films were investigated. Structure characteristics of the sol and asgrown thin films were analyzed by FT-IR spectrum, X-ray diffraction and SEM. The results reveal that the films consisted of CuO phase and SrTiO3 phase have nanocrystalline microstructure at 750°C for 40 min. The modified CuO-SrTiO3 thin films exhibit good resistance-temperature and gas sensitivity properties in a wide range of temperature. The films exposed to 6% CO2 show that sensitivity are 32, and response and recover time are within 2 s at 250 °C operating temperature.

Effect of the Er3+ Concentration on the Luminescence of Ca1-xErxF2+x Thin Films Epitaxially Grown on Si(100)

1993 ◽  
Vol 298 ◽  
Author(s):  
A.S. Barriere ◽  
S. Raoux ◽  
P.N. Favennec ◽  
H. L'haridon ◽  
D. Moutonnet
Keyword(s):  
Thin Films ◽  
Solid Solution ◽  
Substitution Rate ◽  
High Vacuum ◽  
High Energy ◽  
Ultra High Vacuum ◽  
Visible Range ◽  
Doped Semiconductors ◽  
Potential Applications ◽  
Er Doped

AbstractCa1-xErxF2+x thin films, with a substitution rate, x, varying from 1 to 20%, were deposited on Si(100) substrates by sublimation of high purity solid solution powders under ultra-high-vacuum. Rutherford backscattering studies have shown that the films have the composition of the initial solid solution powders, are quite homogeneous and are epitaxially grown on the substrates.The optical properties of these films were studied by means of cathodoluminescence and photoluminescence. At room temperature, the emissions due to the de-excitations from the 4S3/2, 4F9/2, 4I11/2 and 4I13/2 excited levels to the 4I15/2 ground state of Er3+ (4f11) ions are easily detected (λ = 0.548, 0.66, 0.98 and 1.53 μm)The strong 1.53 μm infrared luminescence, which presents evident potential applications for optical communications, is maximum for an erbium substitution rate included between 15 and 17%. These Er concentrations are three or four orders of magnitude greater than the optimum ones in the case of Er-doped semiconductors, which are close to 1018 cm-3. In the visible range, the luminescences are also important.They allow us to detect high energy ion or electron beams. However their maximum efficiencies were observed for a relatively low erbium concentration, close to 1%. These different behaviours are explained by the cross relaxation phenomena, which depopulate the higher levels to the benefit of the 4I13/2 → 4I15/2 transition.The energy distribution of the Stark sublevels of the 4I15/2 state, which results from crystal field splitting, was deduced from a photoluminescence study at 2K. The obtained results show that the environment of the luminescent centres does not change with the erbium concentration.At last, it must be noted that the refractive index of the layers increases with the erbium concentration, leading to the realization of optical guides. Consequently opto-electronic components could be developed from such erbium doped heterostructures.

scholarly journals Pair distribution functions of amorphous organic thin films from synchrotron X-ray scattering in transmission mode

IUCrJ ◽  
2017 ◽  
Vol 4 (5) ◽  
pp. 555-559 ◽  
Author(s):  
Chenyang Shi ◽  
Rattavut Teerakapibal ◽  
Lian Yu ◽  
Geoff G. Z. Zhang
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Amorphous State ◽  
Organic Thin Films ◽  
High Energy ◽  
Transmission Mode ◽  
Organic Thin Film ◽  
Total Scattering ◽  
X Ray ◽  
Wide Range

Using high-brilliance high-energy synchrotron X-ray radiation, for the first time the total scattering of a thin organic glass film deposited on a strongly scattering inorganic substrate has been measured in transmission mode. The organic thin film was composed of the weakly scattering pharmaceutical substance indomethacin in the amorphous state. The film was 130 µm thick atop a borosilicate glass substrate of equal thickness. The atomic pair distribution function derived from the thin-film measurement is in excellent agreement with that from bulk measurements. This ability to measure the total scattering of amorphous organic thin films in transmission will enable accuratein situstructural studies for a wide range of materials.

scholarly journals Correlation of Photocatalysis and Photoluminescence Effect in Relation to the Surface Properties of TiO2:Tb Thin Films

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Damian Wojcieszak ◽  
Danuta Kaczmarek ◽  
Jaroslaw Domaradzki ◽  
Michal Mazur
Keyword(s):  
Thin Films ◽  
Photocatalytic Activity ◽  
Surface Properties ◽  
High Energy ◽  
Rutile Structure ◽  
Current State ◽  
Wide Range ◽  
First Time ◽  
The Relationship ◽  
Deposited Films

In this paper structural, optical, photoluminescence, and photocatalytic properties of TiO2and TiO2:(2.6 at. % Tb) thin films have been compared. Thin films were prepared by high-energy reactive magnetron sputtering process, which enables obtaining highly nanocrystalline rutile structure of deposited films. Crystallites sizes were 8.7 nm and 6.6 nm for TiO2and TiO2:Tb, respectively. Surface of prepared thin films was homogenous with small roughness of ca. 7.2 and 2.1 nm in case of TiO2and TiO2:Tb samples, respectively. Optical properties measurements have shown that the incorporation of Tb into TiO2matrix has not changed significantly the thin films transparency. It also enables obtaining photoluminescence effect in wide range from 350 to 800 nm, what is unique phenomenon in case of TiO2with rutile structure. Moreover, it has been found that the incorporation of 2.6 at. % of Tb has increased the photocatalytic activity more than two times as compared to undoped TiO2. Additionally, for the first time in the current state of the art, the relationship between photoluminescence effect, photocatalytic activity, and surface properties of TiO2:Tb thin films has been theoretically explained.

A Short Review on Raman Studies of Metal Chalcogenide Semiconductor Thin Films

2021 ◽  
Vol 33 (7) ◽  
pp. 1481-1487
Author(s):  
S.M. Ho ◽  
M.H.D. Othman ◽  
M.R. Adam ◽  
K. Mohanraj
Keyword(s):  
Thin Films ◽  
Fluorescence Emission ◽  
Short Review ◽  
Spectroscopic Methods ◽  
Chalcogenide Semiconductor ◽  
Metal Chalcogenide ◽  
Semiconductor Thin Films ◽  
Wide Range ◽  
Crystalline Nature ◽  
Photodiode Arrays

The productions of the thin metallic chalcogenide films are of particular interest for the wide range of fabrication of the solar cells, sensors, photodiode arrays, photoconductors. Raman spectroscopy is used to measure the scattering radiation of a matter. Basically, the spectroscopic methods can be defined as the study of the interaction of electromagnetic radiation with a matter. It can be based on the phenomenon of absorption, fluorescence, emission or scattering. The observation of peaks supported the formation of amorphous or crystalline nature of the samples. In this short review, the authors had gathered some informations about the Raman studies of recently synthesized metal chalcogenide semiconductor thin films.

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